I have this blister that wont pop in between my thigh and scrotum sack, i have had sexual partners that have had sex with me un protected, what is this?

Genital lesions: There are sexually transmitted diseases that show up with lesions. For example, sifilis presents with a solitary non painful lesion. Herpes usually starts with one to a cluster of blisters and is itchy and with burning sensation( painful). Warts which are skin colored and may be one to a cluster of lesions. It could be also a boil that is not sexually transmitted. I advise to have it checked.